There is to be strike action by RMT staff working at Manchester Piccadilly this Saturday, 1 August- https://www.bbc.co.uk/news/articles/c629842g6nlo
Further action is planned for 29 August and 10 October.
It is unclear who is involved, so what the impact (if any) on services will be- it may 'only' be dispatchers, customer services and gateline staff.
It certainly does not involve Train Managers or Drivers.
However it is likely that there will be a picket line outside the main entrance to the station.